KOAN. A koan is a short story that is used as a focus for zazen, with each koan highlighting some form of problem. Originally, 'koan' meant a public case which established a legal precedent. In Zen, it is a paradoxical story assigned to a student to solve, in order to help their awakening or to test the depth of their realization. There are about 1,700 recorded koans (pronounced ko-an in Japanese). Notable collections may be found in the Mumonkan (Gateless Gate) and the Hekiganroku (Blue Cliff Record).
Koan study is a form of practice that requires the supervision of a recognised teacher who has himself or herself gone through this rigorous training. A koan is a brief anecdote recording an exchange between master and disciple or a master's enlightenment experience. Koans are used to bring a student to realization or to help clarify his enlightenment.